# WHMCS\Domain\AdditionalField

`Class` · extends `AbstractModel`

Domain additional fields.

Additional field names are defined in /resources/domains/dist.additionalfields.php

Each TLD requires extra, tld specific information in order to properly register the domain
name with the proper registrar.  Some require information about professional certifications
while others require information proving residency within a specific region of the world.

Instead of having a huge table with all permutations, we instead store these
"additional domain fields" as key/value pairs assigned to the domain name being registered.
Domain registrar modules are then responsible for processing these additional domain
fields for consumption by the proper registrars.

## Methods

### domain

```php
public function domain()
```

Each additional field belongs to one domain.

**Returns** `\Illuminate\Database\Eloquent\Relations\BelongsTo`